Last time I did the turbo I fitted these as my locking tabs looked like they were the originals:
one of these for the manifold to head: (perforated one fitted looked like it had been blowing slightly!)
one of these for the manifold/turbo join:
and one of these for the elbow/downpipe join:
Note that this ^^^ one has a reinforcement ring on the inside to help stop it burning away.
As you've probably gathered, I wasn't wanting anything to leak or come loose this time round!